: nau·seous: \ˈnȯ-shəs, ˈnȯ-zē-əs\
So if you feel compelled to tell me that you're nauseous, I can only assume that you believe yourself to be disgusting and could very well cause me to become ill. If you're feeling sick to your stomach, you might want to claim to be nauseated.
But the biggest annoyance in my life right now is the undetectable something that ails Hot Red Speed. She's still off and on (and off) and very, very vexing.
My car woes have become nauseous.